Red Bull will put a very different car on the track in Melbourne from the model which had disappointed during the last test in Bahrain, Vettel said on Thursday.

Vettel, bidding for a fifth consecutive title, comes into Sunday's race at Albert Park with his team scrambling to come to grips with the new hybrid turbo era in Formula One.

Red Bull, one of four teams using the troubled Renault power unit, was unable to finish a race simulation for either Vettel or his new Australian teammate Daniel Ricciardo, and badly lagged rivals Mercedes and Ferrari in terms of mileage.

“It will be a very different car,” the 26-year-old said at Albert Park.

“Obviously, we had a lot of problems during the tests, we didn't get to test a lot of stuff and we hope to do some more running here.”

Red Bull's struggles to adapt to the new V6 engine have given rival teams hope of ending their four-year stranglehold on the constructors' and drivers' championships, or at a minimum end the German's run of nine consecutive race victories.

Vettel, who has not lost a race since July, said little to lift the gloom hanging over his team's garage, but was adamant that just finishing the race was not the limit of Red Bull's ambitions in Melbourne.

“We know that we are not in the best shape yet. There are a lot of things we need to sort,” said Vettel, a 2011 winner at Albert Park and third last year.

He said, “Unfortunately, you can't solve all of them overnight. We'd love to but we can’t. We really have to go step-by-step together with Daniel. It's no secret you need very, very strong reliability to be a title contender.”

“I'm going out of here not trying to just make it round, I'm going round here to push to the maximum and do the best I can, and then we'll see where we are and how far we get,” he added.

“The target, for sure, is to finish, and the target for sure is to finish in the best possible position. That's the mindset, it's fairly straightforward. We have a strong team, good people on board ... I'm confident we should progress as the season goes on,” he said.